Keyboard player apparatus

ABSTRACT

A PORTABLE PNEUMATIC ACTUATING APPARATUS FOR ACTUATING THE KEYS OF A KEYBOARD MUSICAL INSTRUMENT IS DISCLOSED FOR AUTOMATICALLY PLAYING THE INSTRUMENT. THE APPARATUS HAS A PAIR OF MATING CYLINDER HOUSINGS EXTENDING THE LENGTH OF THE KEYBOARD, EACH HOUSING PROVIDED WITH A LONGITUDINAL SERIES OF CYLINDERS. EACH CYLINDER HOUSING HAS A LONGITUDINAL SURFACE INTERFACTING THE LONGITUDINAL SURFACE OF THE OTHER CYLINDER HOUSING. CHANNELS ARE FORMED IN THE INTERFACING SURFACES. EACH CHANNEL CONNECTS THE UPPER END OF A CYLINDER TO ITS INLET PORT ON A TRACKER BAR. THE INLET PORTS ARE SPACED ALONG A PORTION OF AN EDGE OF THE INTERFACING SURFACES AND THIS PORTION OF THE EDGE SERVES AS THE TRACKER BAR. A LONGITUDINAL OUTLET CHANNEL IS FORMED IN EACH INTERFACING SURFACE FOR CONNECTING THE LOWER END OF EACH CYLINDER TO A VACUUM PUMP. AN UNDERSIZED PISTON IS SLIDABLY MOUNTED IN EACH CYLINDER AND HAS A PISTON ROD CONNECTED TO THE PISTON AND EXTENDING DOWNWARDLY TOWARD A KEY OF THE KEYBOARD. EACH PISTON IS SPRING BIASED TOWARD THE INLET END OF THE CYLINDER AND AWAY FROM THE KEY. THE INTERFACING SURFACES OF EACH CYLINDER HOUSING A SEALINGLY MOUNTED AGAINST OPPOSITE SIDES OF AN IMPERVIOUS MEMBRANE. A PERFORATED MUSIC SHEET IS PASSED ACROSS THE TRACKER BAR EDGE OF THE CYLINDER HOUSING, THEREBY SELECTIVELY BLOCKING AND UNBLOCKING THE INLET PASSAGEWAYS. BLOCKING OF THE INLET PASSAGEWAYS PREVENTS ACTUATION OF THE PISTONS AND THEREBY OF THE KEYS, UNBLOCKING OF THE INLET PASSAGEWAYS PERMITS THE VACUUM PUMP TO MOVE THE PISTON AND ACTUATE THE KEY.

Nov. 16, 1971 D. N. ULRY KEYBOARD PLAYER APPARATUS Filed May 1970 VACUUM 52 r 1 -51? 8O "w so 6 77 89 1 '\:U all N 64 72 F IG 3 INVENTOR.

. DAVID N. ULRY HO BY g U N ATTORNEY Nov. 16, 1971 ULRY 3,620,116

KEYBOARD PLAYER APPARATUS Filed May l5. 1970 L) b'l1u0L.'J--."h mi; 7',

I 90 72 INVENTOR. I 6 DAVID N. ULRY ATTORNEY NOV. 16, 1971 ULRY 3,620,116

KEYBOARD PLAYER APPARATUS Filed May 15, 1970 (5 551100tr;.3h00t 1' TI REJECT 2'9 FIG 7 ROLL END INVENTOR. DAVID N. ULRY ATTORNEY United States Patent Ofice 3,620,116 KEYBOARD PLAYER APPARATUS David N. Ulry, 4380 Donington Road, Columbus, Ohio 43220 Filed May 15, 1970, Ser. No. 37,785 Int. Cl. Gf 3/00 US. Cl. 84-111 2 Claims ABSTRACT OF THE DISCLOSURE A portable pneumatic actuating apparatus for actuating the keys of a keyboard musical instrument is disclosed for automatically playing the instrument. The apparatus has a pair of mating cylinder housings extending the length of the keyboard, each housing provided with a longitudinal series of cylinders. Each cylinder housing has a longitudinal surface interfacing the longitudinal surface of the other cylinder housing. Channels are formed in the interfacing surfaces. Each channel connects the upper end of a cylinder to its inlet port on a tracker bar. The inlet ports are spaced along a portion of an edge of the interfacing surfaces and this portion of the edge serves as the tracker bar. A longitudinal outlet channel is formed in each interfacing surface for connecting the lower end of each cylinder to a vacuum pump. An undersized piston is slidably mounted in each cylinder and has a piston rod connected to the piston and extending downwardly toward a key of the keyboard. Each piston is spring biased toward the inlet end of the cylinder and away from the key. The interfacing surfaces of each cylinder housing are sealingly mounted against opposite sides of an impervious membrane. A perforated music sheet is passed across the tracker bar edge of the cylinder housing, thereby selectively blocking and unblocking the inlet passageways. Blocking of the inlet passageways prevents actuation of the pistons and thereby of the keys; unblocking of the inlet passageways permits the vacuum pump to move the piston and actuate the key.

BACKGROUND OF THE INVENTION The invention relates to pneumatic actuators, and more particularly relates to a pneumatic actuating device for automatically playing the keyboard of a keyboard instrument.

Player pianos have long been a source of enjoyment and amusement. Such pianos are commonly operated by internal pneumatic systems. The traditional pneumatic apparatus is controlled with a series of ports across which a perforated music sheet passes. Player pianos must have the capability of being played either automatically or by a musician. Thus, in order to own a player piano, one had to purchase a specially made piano which could operate in either a manual or an automatic mode.

Other inventors have attempted to construct apparatus which may be added to a conventional piano to convert the conventional piano to one which may be automatically played when desired. The source of difficulty with such conversion apparatus, as with conventional player mechanisms, is the complexity of the mechanisms needed to actuate the keyboard. Conventional systems require several moving parts. For example, the conventional apparatus requires both a switching structure and an actuating structure. A switching structure is required to sense the position of a perforation over a port and to move in response to the presence of that perforation and thereby initiate movement of an actuating device. The switching structure initiates the actuating device, the actuating device then moves to depress the key. Such conventional structures are, for example, shown in patents to Skinner et 3,620,116 Patented Nov. 16, 1971 It is a further object of the invention to provide a I player mechanism which will permit more compact, less expensive, and less complex player devices.

A further object of the invention is to provide a light weight portable player mechanism having a simplified pneumatic system for converting a conventional keyboard musical instrument to automatic playing.

Further objects and features of the invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings illustrating the preferred embodiment of the invention.

SUMMARY OF THE INVENTION The pneumatic actuator for moving a body such as a piano key under selected conditions has a cylinder housing with an enclosed cylinder formed therein. The cylinder has an inlet port communicating with the cylinder relatively near one end of the cylinder and has an outlet port communicating relatively nearer the opposite end of the cylinder. A vacuum pump means is connected to the outlet port for pumping fluid out of the cylinder through the outlet port. An inlet valve means is provided for selectively blocking and unblocking the inlet port. Piston means is also provided for moving in response to the unblocking of the inlet port. The piston means includes a piston which is sufficiently undersized to permit a limited leakage flow of fluid past the piston and out the outlet port when the inlet port is substantially blocked. A piston rod extends from the piston through an opening in the housing for contacting and actuating the body to be actuated. Resilient means is provided for biasing the piston toward the end of the cylinder nearest the inlet port. The resilient biasing means exerts a force on the piston, when the piston is not actuated, which is greater than the force exerted by any pressure differential on the piston when the inlet port is blocked. However, the force of the biasing means, when the piston is actuated, is less than the force exerted by the pressure dilferential on the piston when the inlet port is unblocked. Thus, the piston is actuated by unblocking the inlet port with the valve means to permit substantial movement of the piston.

Another aspect of the invention is the integral cylinder housing in which co-operating pistons are mounted. The cylinder housing has a first interfacing surface and a series of cylinders distributed along but spaced from this interfacing surface. The housing also has a plurality of passageways interconnecting selected ones of the cylinders and suitable inlet and outlet ports, the passageways comprising channels formed in the interfacing surface. Cooperating openings are bored in the interfacing surface to communicate between selected ones of the cylinders and the channels. A fluid impervious membrane is sealingly mounted against the interfacing surface for enclosing the channels.

DESCRIPTION OF THE VIEWS FIG. 1 is a view in perspective of a keyboard player apparatus made according to the invention and mounted in position over the keyboard of a piano;

FIG. 2 is a view in vertical section diagrammatically illustrating the operation of a pneumatic actuator made according to the invention;

FIG. 3 is a view in vertical section taken substantially along the line 33 of FIG. 6 illustrating a preferred embodiment of the invention;

FIG. 4 is a plan view of the preferred embodiment of the invention illustrated in FIG. 1 and FIG. 3;

FIG. 5 is a view in front elevation of the preferred embodiment of the invention illustrated in FIG. 4;

FIG. 6 is an enlarged view in vertical section taken substantially along the line 6-6 of FIG. 3 illustrating the interior of the embodiment of the invention illustrated in FIG. 4; and

FIG. 7 is a schematic view of the circuitry preferred for the operation of the preferred embodiment of the invention.

In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all the technical equivalents which operate in a similar manner to accomplish a similar purpose.

DETAILED DESCRIPTION FIG. 1 illustrates a piano 10 having the automatic player actuating apparatus 12 mounted above its keyboard 14. Vertically adjustable pairs of support pads 15 and 17 are provided at opposite ends of the apparatus. A vacuum pump 16 is connected by suitable tubing and wiring 18 to the actuating apparatus 12, and a music roll 22 is mounted centrally thereon. The actuating apparatus 12, illustrated in FIG. 1, contains several actuators such as the actuator shown diagrammatically in FIG. 2. Preferably, each key has its own actuator.

The actuator for each key is illustrated diagrammatically in FIG. 2 for purposes'of describing the operating principles of the invention. The actuator has an enclosed cylinder housing with an inlet port 32 communicating relatively near one end of the cylinder 31. It also has an outlet port 34 communicating relatively nearer the opposite end of the cylinder 31. A vacuum pump (not shown in FIG. 2) is connected to communicate with the outlet port 34 in order to pump fluid out of the cylinder through the outlet port 34. An inlet valve means is provided for selectively blocking and unblocking the inlet port 32. Diagrammatically illustrated is an inlet valve means which comprises a perforated sheet 36. However, for other types of applications for this actuator, other inlet valves might be used.

A piston means is also provided for moving in response to the positioning of a perforation at the inlet port 32. The piston means includes a piston which is sufficiently undersized to permit a limited, small leakage flow of fluid past the piston 40 and out the outlet port 34 when the inlet port 32 is substantially blocked. Thus, when an imperforate portion of the perforated sheet 36 is positioned over the inlet port 32, some leakage will occur due to the imperfect sealing between the perforate sheet 36 and the inlet port 32. The air or other fluid entering the cylinder by this or other leakage Will pass around the small space 42 existing between the piston 40 and the cylinder 31. As will be seen, a hole or other opening in the piston could operate in an equivalent manner by permitting a similar limited leakage flow. The term undersized has been chosen to describe a piston having a transverse area which is eifectively less than the transverse area of the cylinder. This could even be accomplished by small passages externally connecting opposite ends of the cylinder. I have used a piston with a diameter of 0.810 inch in a cylinder of a diameter of 0.812 inch.

A piston rod 44 extends from the piston 40 through an opening 46 in the housing 30. A relatively soft, antiscratch foot 48 is mounted on the end of the piston rod 44 for contacting the key 50 of the keyboard instrument. A helical spring biasing means 52 urges the piston 40 toward the end of the cylinder 31 nearest the inlet port 32. The force exerted by the biasing means 52 on the piston when the piston is not actuated, and therefore is in the position illustrated in FIG. 2, is greater than the oppositely directed force exerted on the piston by any pressure differential on the piston when the inlet port is blocked. Such a pressure differential might result from the limited flow around the piston 40. However, the force we erted by the biasing means 52 is less than the force exerted by the pressure differential on the piston when the inlet port is unblocked and the flow is greatly increased. Thus, when the inlet port 32 is unblocked by the movement of a perforation over the inlet port 32, the inrush of air into the cylinder 31 moves the piston 40 to a position 40a illustrated in phantom in FIG. 2. This movement moves the piston rod 44 and its foot 48 down against the key 50 to move it to the position 50a also shown in phantom in FIG. 2.

Therefore, the piston 40 is retained in its unactuated position illustrated in FIG. 2 while the inlet port 32 is substantially blocked. Although in this condition there Will be some leakage of air into the cylinder 31, the interior of the cylinder 31, is nonetheless maintained by the vacuum pump at a pressure below atmospheric pressure and substantially equalized on both sides of the piston 40. However, when the inlet port 32 is unblocked, atmospheric pressure forces a rush of air into the cylinder 31 which cannot pass freely through the gap 42 around the piston 40. Thus, a great pressure differential is created across the piston 40 moving it against the force of the biasing means 52 to the position 400. So long as the inlet port 32 remains unblocked, the piston 40 Will remain in its position 40a shown in phantom. When the inlet port 32 is again blocked, the piston will return to its initial position illustrated in FIG. 2.

FIGS. 36, inclusive, illustrate the preferred embodiment of the invention. The following description of this embodiment simultaneously refers to all four of these figures.

The preferred apparatus has a first cylinder housing 60 having a first interfacing surface 62. It also has a similar second cylinder housing 64 with its second interfacing surface 66. Each housing has a series of cylinders such as the cylinder 70 in the first housing 60, and the cylinder 72 in the second housing 64. Each cylinder, such as the cylinder 72, has an inlet passageway connecting one end of the cylinder to its own inlet port such as the inlet port 74. This inlet passageway for the cylinder 72 includes a channel 76 formed in the second interfacing surface 66 and further includes a co-operating opening 78 bored into the second interfacing surface 66 and communicating between the channel 76 and the cylinder 72. Each cylinder is provided with a similar passageway comprising an inlet port, channel, and opening. These channels are shown more clearly in FIG. 6. Each channel leads to an inlet port, and the inlet ports for all the cylinders are spaced along an edge 80 of the interfacing surface. This edge 80 functions as a tracker bar across which the perforated music sheet is passed to selectively block and unblock the inlet ports. The tracker bar is therefore an integral part of the cylinder housing. The channels which are formed in the interfacing surfaces are preferably enclosed on their remaining side by a fluid impervious membrane 89 sandwiched between the interfacing surfaces and sealingly attached against each surface. If the spacing of the channels permitted, the separate membrane can be eliminated and the channels could be staggered so that the interfacing surface opposite each channel would serve to enclose the channel in an equivalent manner.

An outlet channel 90 is also provided in the interfacing surface 66. The outlet channel 90 parallels the series of cylinders and is connected to an outlet which in turn communicates with the vacuum pump 16. A plurality of openings are formed between the outlet channel and each cylinder. For example, the bore 92 illustrated in FIG. 3 and FIG. 6 connects the outlet channel 90 to the cylinder 72. An additional channel 100 is provided in which to pass the electrical wiring described below. The plurality of cylinders, such as cylinders 70 and 72, which are molded or bored in the cylinder housings 60 and 64, house pistons such as the pistons 102 and 104' which are substantially like the piston illustrated in FIG. 2 and operate in a similar manner. The cylinders are enclosed by end caps such as the end caps 110 and 112. .The pistons of one cylinder housing 64 register with the black piano keys while the pistons of the other cylinder housing 60 register with the white keys.

FIGS. 4 and 5 show the rewind spool 120 and the drive spool 122 on which the perforated music sheet is wound. The perforated music sheet is initially stored in a wound roll on the rewind spool 120 and in playing is wound onto the drive spool 122. For relay, the sheet is rewound onto the rewind spool 120. The spool drive and rewind motors and axles and the control circuitry are housed in the compartments 130 and 132 positioned at opposite ends of the tracker bar 80. A portion of the compartment 132 is shown broken away in FIG. 5 to reveal the drive motor 140.

The preferred control circuitry is illustrated schematically in FIG. 7. Although it utilizes two special purpose micro switches 201 and 203, modifications to provide conventional circuitry will be obvious to those skilled in the electronic arts. The micro switch 201 is a single pole double throw switch which is provided with a latch for holding its wiper 205 against its contact 207. The micro switch 203 is a single pole single throw switch which is parallel connected across a start button switch 209. A reject button 211 is mechanically arranged to move the wiper 205 of the switch 201 from its latched position against the contact 207, to a position against the contact 213. The reject button may be manually actuated or it may be electrically actuated by energization of its actuating coil 215.

A mechanical arm 217, shown diagrammatically, is connected to an arm 150 which is illustrated in FIG. 4 and FIG. 5. The arm 150 is pivotally mounted and biased to extend into a circular groove 152 on the drive spool 122 when there is no music sheet wound on the drive spool 122. Whenthe arm 150 extends into the groove 152 the switches 201 and 203 and the arm 217 are in the positions illustrated in FIG. 7. When the music sheet moves the arm 150 out of the groove 152, the arm 217 moves to the position illustrated in phantom in FIG. 7 permitting the micro switch 203 to make contact.

-A roll-end switch 219 is series connected to the reject actuator coil 215. The roll-end switch 219 is mechanically linked to a' special piston which in turn is pneumatically connected to an inlet port on the tracker bar which signals the end of a musical composition. Thus, when the music is completed, a corresponding perforation opens this inlet port before the sheet detaches from the rewind spool 120. This actuates the reject button 211.

The drive motor 140 is series connected to its speed control rheostat 223 and a vacuum .pump motor 225 is similarly connected to its volume control rheostat 227. Both are connected to the terminal 207 of the micro switch 201. The music tempo may be controlled by adjusting the drive motor speed control rheostat 223 by means of a knob 170, illustrated in FIG. 4 and FIG. 5. The piano volume may be controlled by adjusting the vacuum pump volume control rheostat 227 to thereby vary the intensity with which the keys are struck. A control knob 173, shown in FIG. 4 and FIG. 5, controls the piano volume in this manner. A rewind motor 229 is connected to the terminal 213 of the micro switch 201.

The operation of the control circuit begins by threading.

the music sheet from the rewind spool 120 onto the drive spool 122. The start button 209 is then depressed to immediately energize the drive motor and the vacuum pump 225. This winds a layer of music sheet onto the drive spool 122, moves the arm 217 to its position shown in phantom to actuate the switch 203. Making of the switch 203 permits release of the start button 209. The player mechanism may continue to operate and play the InllSlC.

If, however, the operator desires to reject the music and cause rewind of the music sheet, he depresses the reject button 211. This unlatches the micro switch 201 and moves its wiper 205 against the contact 213. The drive motor 140 and the vacuum pump 225 cease operating and the rewind motor 229 begins operation. The rewind motor 229 continues until the music sheet is detached from the drive spool 122 and the arm moves into the circular groove 152. Movement of the arm 150 into the groove returns the switches 201 and 203 to the positions shown in FIG. 7, thus de-energizing the entire circuit.

If, instead of rejecting the music, the operator permits it to play to the end, then the roll end switch 219 will actuate the reject button when the music is completed and the sequence of operation will be the same as described above for manual rejection.

From the above, it can be seen that this invention offers two primary advantages. First, the pistons operate both as a switching means and an actuating means. The actuator mechanism, apart from the drive circuitry, has but a single moving body. Second, by providing the pneumatic circuitry in the form of channels and bores in a surface, many pneumatic connections can be made in a small volume of equipment and at a low cost. Clearly, such channels and bores are far less expensive to manufacture and more reliable than the inter-connection of tubing and fittings.

It is to be understood that while the detailed drawings and specific examples given describe preferred embodiments of my invention, they are for the purposes of illustration only, that the apparatus of the invention is not limited to the precise details and conditions disclosed, and that various changes may be made therein without departing from the spirit of the invention which is defined by the following claims.

I claim:

1. A keyboard actuating apparatus for operating a keyboard in response to the movement of a perforated sheet over tracker bar inlet ports, the apparatus having a vacuum pump and comprising (a) a cylinder housing mounted opposite said keyboard and having an interfacing surface, the housing having a series of cylinders formed therein axially transverse the keyboard and distributed along but spaced from said interfacing surface, said housing having a plurality of inlet channels formed in the interfacing surface, each channel extending from a common linear edge forming said tracker bar inlet ports to a bore near an end of a dilferent cylinder distally from the keyboard, the housing also having an outlet channel formed in said surface communicating with said vacuum pump and having a plurality of openings in said outlet channel each communicating near the proximal end of a diiferent one of said cylinders;

(b) piston means in each cylinder comprising (1) an undersized piston slidable in its cylinder and being sufiiciently undersized to permit a limited leakage flow of air past the piston and to the vacuum pump when its cooperating inlet port is substantially blocked; r

(2) a piston rod extending from the piston through an opening in said housing and toward said keyboard sufliciently distant to depress a key when the piston slides toward the key; and

7 (3) resilient means biasing the piston distally from the keyboard and exerting a force on the piston which is greater than the force exerted by a pressure dilferential on the piston when the inlet port is blocked but which is less than the force exerted by a pressure differential on the piston when the inlet port is unblocked; and (c) an impervious membrane sealingly mounted against the interfacing surface for enclosing said channels. 2. An apparatus according to claim 1 wherein a second similar cylinder housing has its interfacing surface sealingly mounted against the opposite surface of said membrane and contains similar piston means.

References Cited UNITED STATES PATENTS Kisker 84-160 X Meade 84-160 X Salyer 84111 X Burton 84152 X \Klein 84-155 OKeefe 235-201 X PF [RICHARD B. WILKINSON, Primary Examiner L. R. PRANKDI'N, Assistant Examiner 

